Defensive players to watch

There are few guarantees in the NFL, but one of the rare ones is, if the Bears’ defense doesn’t make significant improvement in 2014, it will once again be an 8-8 team, or worse.

While the belief things will be better on defense in Chicago is rampant because of a huge influx of veteran free agents, and the use of four of their first five picks in the draft on defense, we’ve received no proof so far this preseason.

The Bears’ second preseason game today against Jacksonville could offer some comfort. Here are five key players to watch:

1. Will Sutton: Veterans Jared Allen and Jeremiah Ratliff may bring stability and occasional playmaking impact, but at best both are well down the home stretch of their careers. Sutton looked to me to be the best three-technique tackle in this year’s draft, and could make a huge impact sharing time at the three with Ratliff, if he’s NFL ready. I’ve seen the lightning first step in Bourbonnais that might make him a disruptive force in opposing teams’ backfields, but now it’s time to see it in an NFL game against at least second-team competition, if not the 1s.

2. Jon Bostic: Bostic was having an excellent training camp until the first preseason game against the Eagles, when he appeared to have forgotten everything he’d learned during the offseason. His natural position is weakside linebacker, which he will not get a crack at as long as Lance Briggs is a Bear. But he will be on the field with Briggs whenever the Bears are in the nickel, and he needs to make some plays against the Jags, or at least be in the right place at the right time a lot more than he was as a rookie ... or in the Eagles game.

3. Christian Jones: It’s difficult to project an undrafted rookie free agent even making the team, let alone earning meaningful playing time, but Jones is the only true natural strongside linebacker on the roster. He would have been a mid-round draft pick were it not for a diluted drug test, and he needs to prove it against the Jags to generate some urgency in the competition for linebacker spots on the roster.

4. Adrian Wilson: With all the veteran safeties the Bears have in camp, we know Wilson is the only one who can actually move the needle on this defense if he has anything left. The Bears need to know sooner rather than later to help sort out the rest of the group.

5. Brock Vereen: After running with the No. 1s through most of the offseason OTAs and minicamp, Vereen was demoted early in camp, and it’s not really clear why. The Bears said it was to see how he’d handle adversity. Apparently, not so well, since he hasn’t been back with the first team since. All of the vets at safety are career journeymen, with the exception of Wilson. If Vereen can’t play Robin to Wilson’s Batman, it’s unlikely the Bears will take a meaningful step forward at the position.